Conventional methods for designing freeform surface imaging optical system comprise steps of finding a good starting point, and then conducting a computer-aided optimization.
However, conventional methods are not very intelligent and automated; and a function of conventional methods is not yet enough. For example, conventional methods highly rely on the starting point, if a difference between the structure and parameters of the starting point and that of design requirements is big, it may take a long time to optimize. Moreover, for the imaging optical systems with advanced specifications and special configuration, it may not be able to find an appropriate starting point. An optimization process is a combination of “science” and “art”, a software optimization algorithm, people's guidance and intervention in the optimization process, and people's experience and skills are important. Thus, a whole design process is highly dependent on human effort.